[0001] The invention relates to an indexing-motion packaging apparatus for an indexing-motion
packaging machine according to the features of the preamble of claim 1. The invention
further relates to a packaging apparatus for a packaging machine according to the
features of the preamble of claim 5.
[0002] US-A-5,170,611 and
US-A-5,205,110, the disclosures of which are hereby incorporated herein by reference, disclose indexing
motion apparatuses and methods for vacuum packaging of articles such as hot dogs,
sliced luncheon meat, cheese or pharmaceuticals.
[0003] The packaging apparatus that forms the starting point of the invention (
EP-A-2 253 543,
EP-A-2 253 544) is part of an indexing-motion packaging machine including a web transport conveyor
that transports webs of flexible packaging material from upstream to downstream locations
through a series of stations. A typical packaging apparatus includes a forming station
and a closing station, each having a movable die member that a counterbalanced using
a lift that moves both die members. The disclosure of
EP-A-2 253 543 and
EP-A-2 253 544 is hereby incorporated herein by reference.
[0004] The object of the present invention is to improve the construction of the prior art
indexing-motion packaging apparatus.
[0005] Above object is met by an indexing-motion packaging apparatus comprising the features
of the preamble of claim 1 and in combination therewith the features of the characterizing
part of claim 1. Preferred modifications and improvements of the teaching of claim
1 are the subject matter of the dependent claims 2 to 4.
[0006] In another version of the teaching of the invention above mentioned object is met
with a packaging apparatus according to the preamble of claim 5 that has in combination
with the features of characterizing part of claim 5. Preferred modifications and improvements
of this teaching are the subject matter of the dependent claims 6 to 12.
[0007] An indexing-motion packaging machine comprises a web transport conveyor transporting
a web of flexible packaging material from upstream to downstream locations through
a series of stations including a forming station for forming at least one pocket in
the web, a loading station for placing food product in the pocket, and a closing station
for closing the pocket with another web of packaging material. In the machine, the
packaging apparatus according to claim 1 comprises a forming station comprising first
and second forming die members, at least one of the first and second forming die members
being movable between open and closed positions relative to the other of the first
and second forming die members to form the pocket, a closing station comprising first
and second closing die members, at least one of the first and second closing die members
being movable between open and closed positions relative to the other of the first
and second closing die member to close the pocket, and a lift that operatively couples
at least three members of the first and second forming die members and first and second
closing die members together such that operation of the lift counterbalances and moves
the three members together between the respective open and closed positions.
[0008] According to claims 2 to 4 there are disclosed specific structural features relating
to the construction of the lift and its connections to the movable die members.
[0009] The packaging apparatus according to claim 5 is intended for handling a specific
type of packaging material for the food product. The food product has packaging material
comprising a foldable flap extending generally outwardly away from the conveyor. The
packaging apparatus comprises a closing station located downstream of the loading
station and for closing the pocket with a second web of packaging material. The second
web of packaging material is oriented in the closing station so as to engage with
the first web of packaging material and also fold the foldable flap downwardly with
respect to the conveyor as the conveyor moves from upstream to downstream.
[0010] The dependent claims relating to the packaging apparatus of claim 5 are addressing
constructional features of the apparatus. In particular claim 7 is addressing a specific
construction with at least one movable dog located upstream of the engagement between
the first and second webs of packaging material. Further features of the claims relate
to specific features of the movable dog or dogs. Claim 9 relates to a control circuit
and its specific features.
[0011] It should be expressly mentioned that the features of any of claims 1 to 4 on the
one hand and the features of any of the claims 5 to 12 on the other hand may be combined
in a single packaging apparatus.
[0012] Embodiments of packaging apparatuses and methods are described with reference to
the following Figures. The same numbers are used throughout the Figures to reference
like features and components.
- Fig. 1
- is a perspective view of a packaging machine,
- Fig. 2
- is a side view of the packaging apparatus in the packaging machine,
- Fig. 3
- is an interior section view of the packaging apparatus,
- Fig. 4
- is an interior section view of the packaging apparatus,
- Fig. 5
- is a perspective view of a closing station in the packaging machine,
- Fig, 6
- is a side sectional view of the closing station of Fig. 5,
- Fig. 7
- is an exploded view of the closing station,
- Figs. 8-10
- are like Fig. 6 and depict movement of food product and packaging through the closing
station.
[0013] In the present description, certain terms have been used for brevity, clearness and
understanding, No unnecessary limitations are to be inferred therefrom beyond the
requirement of the prior art because such terms are used for descriptive purposes
only and are intended to be broadly construed. The different apparatus and methods
described herein may be used alone or in combination with other systems and methods.
[0014] Figs. 1 and 2 depict an indexing motion packaging machine 2 that includes a web transport
conveyor 4 transporting a web 6 of flexible packaging material along a direction of
transport depicted by arrows 8 from upstream to downstream through a series of stations
including a forming station 10 for forming at least one pocket in the web 6, a loading
station 12 for placing food product in the pocket and a closing station 14 for closing
the pocket with another web 16 of flexible packaging material. In the examples depicted,
the machine 2 also optionally includes a cutting station 18 for separating the closed
pockets into individual food containing packages.
[0015] As depicted in Fig, 2, the various components of the machine are mounted to and supported
by a frame 20 including spaced parallel upper and lower frame members 22 and vertical
frame members 24. A series of legs, e.g. 26, support machine 2 above the ground. A
supply roll 28 supplies the web 6. The supply roll 28 rotates about an unwind shaft
30 to supply the web 6 along the direction 8. An unwind motor (not shown) drives a
set of rollers and a timing pulley to safely pull the web 6 from the supply roll 28
and along the conveyor 4 in an indexing manner and to allow a series of operations
at the forming station 10, loading station 12, closing station 14, and cutting station
18 for creating a packaged product. A supply roll 32 supplies the web 16 along an
arcuate path 21 (as will be described further herein below) to engage and close the
noted pocket. The rotational operation of the supply rolls 28 and 32 is similar to
the operation of the supply roll arrangement depicted in
U.S. Patent No. 5,205,110, incorporated herein by reference. For brevity, further description of the supply
rolls 28 and 32 and their functions are not provided herein. It will be understood
by those skilled in the art that any arrangement for safely supplying a web of flexible
packaging material along a web transport direction is suitable for use with the presently
described embodiments.
[0016] As shown in Figs. 2-4, packaging apparatus 34 is incorporated into the machine 2.
The apparatus 34 includes the forming station 10, which includes first and second
forming die members 36, 38 that mutually cooperate to form the pocket in the web 6.
In the embodiment shown, the first forming die member 36 includes a die box connected
to a vacuum supply for vacuum forming the pocket in the web 6. The first forming die
member 36 is movable away from and towards the second forming die member 38 between
an open position to allow movement of the web 6 in the direction 8 and a closed position,
wherein the forming die member 36 engages with the forming die member 38 to sandwich
the web 6 therebetween and receive a vacuum to assist in formation of the noted pocket
in the web. Vacuum forming of a web is described in the incorporated
US-A-5,205,110. It will be understood by those skilled in the art that arrangements other than that
disclosed in
US-A-5,205,110 for forming a pocket in the web 6 are suitable for use in combination with the presently
described embodiments and in addition to or instead of the arrangement described in
US-A-5,205,110. In addition, although the forming station 10 depicted and described includes a forming
die member 36 that is movable relative to a stationary forming die member 38, those
skilled in the art will recognize that the forming station 10 could instead include
forming die members 36, 38 that are both movable relative to each other.
[0017] The apparatus 34 also includes the closing station 14 including first and second
closing die members 42, 44, which mutually cooperate to close the noted pocket in
the web with the second web 16 of flexible packaging material. In the embodiment shown,
the closing die member 42 includes a die box that cooperates with a heat sealing mechanism
to seal the web 16 to the web 6 in a manner similar to that described in
US-A-5,205,110. Both closing die member 42 and closing die member 44 are movable between an open
position to allow movement of the web 6 in the direction 8 and a closed position to
close the pocket with the web 16.
[0018] In the example shown, the forming die member 36 and closing die members 42, 44 are
counterbalanced so that movement of one of these members towards its closed position
assists movement of the others of these members towards their closed positions, and
so that movement of one of these members towards its open position assists movement
of the others of these members towards their open positions. The counterbalanced interrelationship
between the die members 36, 42 and 44 can be accomplished in different ways. In the
embodiments shown, the forming die member 36 is inverted with respect to the closing
die member 42 and the forming station 10 is located below the closing station 14 in
the machine 2. In this respect, the forming station 10 and closing station 14 are
oriented such that the web 6 enters the forming station 10 from one direction shown
at arrow 46 and enters the closing station 14 from the other, opposite direction shown
at arrow 48.
[0019] Counterbalancing between the respective die members 36, 42 and 44 is facilitated
by a lift 50 operatively coupling the forming die member 36 and closing die members
42, 44. The lift 50 can include different mechanisms that facilitate counterbalanced,
driven motion between the respective die members 36, 42 and 44, so that the movement
of the lift 50 moves the forming die member 36 towards its closed position and the
closing die members 42, 44 towards their closed positions, and so that opposite movement
of the lift 50 moves the forming die member 36 towards its open position and the closing
die members 42, 44 towards their open positions.
[0020] In the embodiments shown, the respective die members 36 and 42 are inverted with
respect to each other and the lift 50 is disposed between the forming station 10 and
the closing station 14. The lift 50 is located vertically higher than the forming
station 10 and vertically lower than the closing station 14. In operation, the lift
50 rotates in a first direction to move the respective die members 36, 42 away from
each other towards their respective closed positions. A pair of links 40 on each side
of the apparatus (which together make four links) connects the die member 36 to the
die member 44 such that the die members 36, 44 move together during operation of the
lift 50. The number and location of links 40 can vary. Link 40 has an upper end 52
that is pivotably connected to the closing die member 44 at a pivot point 54 and a
lower end 56 that is pivotably connected to the sealing die member 36 at a similar
pivot point 58. In this manner, the die member 44 is coupled to and moves into its
closed position at the same time as the die member 36. The lift 50 rotates in a second,
opposite direction to move the respective die members 36, 42 towards each other and
towards their respective open positions. Simultaneously, movement of the die member
36 is reflected in the die member 44 via the operable connection at links 40. Thus,
the die member 44 also moves into its respective open position.
[0021] Referring to Figs. 3 and 4, movement of lift 50 facilitates counterbalanced motion
between the respective die members as described in the incorporated
EP-A-2 253 543 and
EP-A-2 253 544. As described in those applications, the lift 50 can be operably driven by a motor,
which in one example includes a servo motor. This type of arrangement is described
there for example in Figs. 3-8, and the related description thereof. Briefly, the
respective die members 36, 42 are inverted with respect to each other and the lift
50 is disposed between the forming station 10 and the closing station 14. The lift
50 is located vertically higher than the forming station 10 and vertically lower than
the closing station 14. In operation, the lift 50 rotates in a first direction shown
at arrow 62 (Fig. 3) to move the respective die members 36, 42 towards each other
and towards their respective open positions. The lift 50 rotates in a second, opposite
direction shown at arrow 60 (Fig. 4) to move the respective die members 36, 42 away
from each other and towards their respective closed positions.
[0022] Movement of lift 50 facilitates counterbalanced motion between the respective die
members 36,42,44. In the example shown, the lift 50 includes a pair of drive arms
64 on each side of the apparatus 34. One drive arm 64 is shown in Figs. 3 and 4. Drive
arm 64 rotates about a pivot axis 59 and has a first end operatively connected to
the closing die member 42 and a second, opposite end operatively connected to the
forming die member 36. The lift 50 also includes a drive wheel 66 (Fig. 2) operatively
connected to the drive arms 64. This can be accomplished in different ways. As described
in the above-incorporated applications, rotation of the drive wheel 66 causes rotation
of the drive arms 64 about the pivot axis 59 and causes movement of the interconnected
closing die member 42, the forming die box 36 and the closing member 44 into and out
of the respective open and closed positions,
[0023] In the example shown, the lift 50 also includes a follower wheel 68 (Fig. 2) that
is operatively connected to the drive wheel 66 so that rotation of the drive wheel
66 causes rotation of the follower wheel 68. Connection of the follower wheel 68 to
the drive wheel 66 can be accomplished in different ways. In the example shown the
connection is accomplished by a belt 70 that operatively connects the follower wheel
68 to the drive wheel 66.
[0024] A pair of follower arms 72 is operatively connected to the follower wheel 68 so that
rotation of the follower wheel 68 causes rotation of the follower arms 72. One follower
arm 72 is shown in Figs. 3 and 4. Rotation of the follower arms 72 can be accomplished
in different ways, and in the example shown is accomplished by connection of the follower
wheel 68 to a rotatable shaft to which the follower arms 72 are keyed so that the
follower arms 72 rotate concentrically and along with the follower wheel 68, Each
follower arm 72 has a first end operatively connected to the movable first closing
die member 42 and a second, opposite end operatively connected to the forming die
member 36. As explained further below, rotation of the follower arms 72 causes movement
of the closing die member 42 and the forming die member 36 into and out of the open
and closed positions.
[0025] A servo motor 74 (Figs. 3 and 4) is connected to the drive wheel 66 by a belt 76
and operatively drives the drive wheel 66 into rotation in a back and forth direction.
This causes drive arms 64 to rotate back and forth between the positions shown in
(Figs. 3 and 4), Rotation of the drive wheel 66 is translated to follower wheel 68
via belt 70 and thus causes rotation of follower wheel 68 in the same timing and orientation.
Rotation of follower wheel 68 causes rotation of follower arms 72 back and forth between
the positions shown in (Figs. 3 and 4).
[0026] Referring to (Figs. 3 and 4), respectively, pivoting movement of the drive arms 64
and follower arms 72 causes movement of the die members 36, 42 into and out of the
noted open and closed positions, This can be accomplished in different ways. In the
example shown, first ends of the drive arms 64 travel along guide tracks 78 operatively
connected to the closing die member 42 and the second ends of the drive arms 64 travel
along guide tracks 80 operatively connected to the forming die member 36. Both of
the guide tracks 78, 80 include first and second rails. Bearings 82 are operatively
connected to the ends of the drive arms 64 and are disposed between and configured
to ride along the rails of the guide tracks 78,80.
[0027] Follower arms 72 also have bearings that ride in guide tracks 78, 80 including rails.
The structure and operation of the follower arms 72 is thus driven by and follows
the operation of the drive arms 64, Operation of the servo motor 74 thus causes rotation
of both the drive arms 64 and the follower arms 72 to move the movable die members
36, 42 into and out of the open and closed positions shown in Figs. 3 and 4, respectively.
Specifically, rotation of the drive arms 64 causes bearings 82 to ride along guide
tracks 78, 80 and push the forming die member 36 and closing die member 42 into and
out of the open and closed positions. In the same way, rotation of the follower arms
72 causes bearings 82 to ride along the guide tracks 78, 80 and push the forming die
member 36 and closing die member 42 into and out of the open and closed positions.
Simultaneously, movement of the forming die member 36 is reflected in the closing
die member 44 because of the operative coupling by links 40.
[0028] Now referring to Figs. 5 and 6, the closing station 14 is located downstream of the
loading station 12. The closing station 14 can be configured for closing the noted
pocket in the lower web 6 with the upper web 16. The particular example shown in the
Figs. is configured for use with a food product having an intermediate packaging material
comprising a foldable flap 84 extending generally upwardly or outwardly with respect
to the conveyor 4. This type of intermediate packaging is often utilized in packaging
of food product, for example, sliced bacon 86 or other sliced and non-sliced products.
The foldable flap 84 is part of a paper product material often referred to as a "J
board" or an "L board" 88, which can be a folded sheet of cardboard or similar material.
The bacon 86 and L board 88 are manually- or machine-loaded into a respective pocket
in the web 6 at the loading station 12 in an orientation wherein the foldable flap
84 of the L board 88 extends generally outwardly or vertically with respect to the
conveyor 4 and is foldable down onto the bacon 86 as shown at arrow 90 in Fig. 6.
The embodiment shown in the Figs. includes a web transport conveyor 4 carrying pair-wise
arrangements of L boards 88 carrying bacon 86. At index of the conveyor 4, two pairs
of L boards 88 are moved. This is only one example and the conveyor 4 can be configured
to carry more or less packages per index length and width.
[0029] The closing station 14 includes an apparatus for folding the flap 84 of the L board
88 in the direction of arrow 90 such that the flap 84 overlaps the bacon 86 during
the closing process. In the example shown, a plurality of movable dogs 92 rotates
with a rotating shaft 94 located above and extending transversely relative to the
conveyor 4. The shaft 94 can be driven into rotation by a motor 95, which can for
example include a servo motor or other type of motor for operatively rotating the
shaft 94. Dogs 92 includes at least one finger for engaging an upstream side 96 of
the foldable flap 84. The particular configuration of the dog 92 can vary. In the
example shown, dog 92 has a Z-shape in cross section and includes a pair of oppositely
oriented engagement fingers 98. Rotation of the rotatable shaft 94 and the dogs 92
is properly timed with the indexing motion of the conveyor 4 such that the engagement
fingers 98 engage with and force the upstream side 96 of the flap 84 to fold in the
direction of arrow 90 at each 180-degree rotation of the dogs 92.
[0030] In one example, a programmable microprocessor or control circuit 97 is provided so
that control of the positioning of the dogs 92 can be accomplished by an electronically
created cam. In this example, the control circuit 97 is programmed to control the
rotational orientation of the dogs 92 such that the dogs 92 are electronically linked
to the horizontal position of chains on the conveyor 4 that advance the L board 88.
This can be accomplished in such a manner that produces a precisely timed movement
for index advancement of the L board 88 on the conveyor 4. This movement profile can
be created by incrementally advancing the L board 88 on the conveyor 4 and then rotating
the dogs 92 forwardly to a correct position in relation to the L board 88, sensing
this position with a sensor, such as proximity sensor 120, and subsequently recording
this position in a memory of the control circuit 97. By collecting these positions
in the memory of the control circuit 97, the control circuit 97 can thereafter access
the memory and control the servo motor 95 so as to accomplish a precise movement that
is linked to the movement of the L boards 88 on the conveyor 4. This results in a
non-linear rotational movement of the dogs 92, which is repeated when a linear index
movement of the conveyor 4 occurs and that is adapted to changes in the speed of the
index.
[0031] As shown in Figs. 6 and 7, immediately downstream of the dogs 92 is a series of guide
bars 100. As the conveyor indexes from upstream to downstream, and immediately after
the dogs 92 fold the flap 84 from a first generally vertical orientation shown at
102 to a second generally angled (or folded) orientation shown at 104, the guide bars
100 engage with the upstream side 96 of the flap 84 and prevents the flap 84 from
biasing back into the generally vertical orientation 102.
[0032] Conveyor 106 guides the web 16 to a location adjacent to the downstream end 108 of
the guide bars 100. As the bacon 86 is indexed on the web 6 by the conveyor 4 past
the downstream end 108 of the guide bars 100, the conveyor 106 causes the web 16,
travelling along an arcuate path defined by conveyor 106, to engage the upstream side
96 of the foldable flap 84 and further fold the flap 84 onto the bacon 86. The web
16 is thus advantageously positioned by the conveyor 106 with respect to the guide
bars 100 so that the flap 84 is maintained in a first folded position until the pocket
is closed into a second folded position via engagement with the top web 16.
[0033] As the bacon 86 is indexed downstream, the closing station 14 further closes (e.g.
seals) the package by mating the web 16 with the web 6 in a conventional manner. The
flap 84 of the L board 88 is efficiently folded down onto the bacon 86 at the time
of mating.
[0034] Fig. 7 depicts an exploded view of a portion of the closing station 14, showing the
plurality of movable dogs 92 and the series of guide bars 100. The dogs 92 are supported
for rotation along the rotating shaft 94, which is driven into rotation by the servo
motor 95. As discussed above, the servo motor 95 is controlled by the control circuit
97. The rotating shaft 94 is supported for rotation by opposing brackets 110 and at
one end by a bearing 112. A cover 114 can be provided on the assembly. The guide bars
100 are supported by a top plate 116 and can be adjusted with respect to the conveyor
4 by adjustment connections 118, which can be screws, for example.
[0035] Figs. 8-10 depict the dogs 92 during rotation to fold the foldable flap 84 down onto
the bacon 86 through one index of the conveyor 4. As shown in Fig. 8, the first engagement
finger 98 engages with the upstream side 96 of the L board 88. Referring to Figs.
9 and 10, as the dog 92 rotates and the conveyor 4 indexes, the upstream side 96 of
the L board 88 is positioned beneath the guide bar 100. This can be seen in series
from Figs. 8 through 10. During this movement, the proximity sensor 120 can sense
position of the trigger 122 and communicate same to the control circuit 97 for saving
in the memory, as described above.
[0036] Although only a few example embodiments have been described in detail above, those
skilled in the art will readily appreciate that many modifications are possible in
the example embodiments without materially departing from this invention. Accordingly,
all such modifications are intended to be included within the scope of this disclosure
as defined in the following claims,
1. An indexing-motion packaging apparatus for an indexing-motion packaging machine,
the packaging machine comprising a web transport conveyor (4) transporting a web (6)
of flexible packaging material from upstream to downstream locations through a series
of stations including a forming station (10) for forming at least one pocket in the
web (6), a loading station (12) for placing food product in the pocket, and a closing
station (14) for closing the pocket with another web (16) of packaging material,
wherein the packaging apparatus (34) comprises
the forming station (10) comprising first and second forming die members (36, 38),
at least one of the first and second forming die members (36, 38) being movable between
open and closed positions relative to the other of the first and second forming die
members (36, 38) to form the pocket, and
the closing station (14) comprising first and second closing die members (42, 44),
at least one of the first and second closing die members (42, 44) being movable between
open and closed positions relative to the other of the first and second closing die
member (42, 44) to close the pocket,
characterized in that
a lift (50) is provided that operatively couples at least three members (36,42,44)
of the first and second forming die members (36, 38) and first and second closing
die members (42, 44) together such that operation of the lift (50) counterbalances
and moves the three members (36, 42, 44) together between the respective open and
closed positions.
2. The apparatus according to claim 1, characterized in that the first and second closing die members (42, 44) are both movable between open and
closed positions to close the pocket and the lift (50) operatively couples the movable
forming die member (36) and the first and second closing die members (42, 44) together
such that operation of the lift (50) moves the movable forming die member (36), the
first closing die member (42) and the second closing die member (44),
wherein, preferably, the lift (50) comprises at least one link member (40) extending
between the movable forming die member (36) and at least one of the first and second
closing die members (42, 44) and, further preferably, the link (50) comprises a first
end (56) that is pivotably coupled to the movable forming die member (36) and a second
end (52) that is pivotably coupled to the at least one of the first and second closing
die members (42, 44),
3. The apparatus according to claim 2, characterized in that
the lift (50) rotates in a first direction to move the movable forming die member
(36) towards its closed position and the first and second closing die members (42,
44) towards their closed positions and the lift (50) rotates in a second, opposite
direction to move the movable forming die member (36) towards its open position and
the first and second closing die members (42,44) towards their open positions.
4. The apparatus according to claim 1, 2 or 3 characterized in that
it comprises a servo motor operating the lift (50),
5. A packaging apparatus for a packaging machine,
the machine comprising a web transport conveyor (4) transporting a web (6) of flexible
packaging material from upstream to downstream locations through a series of stations
including a forming station (10) for forming at least one pocket in a first web (6)
of packaging material and a loading station (12) for placing food product in the pocket,
the food product having packaging material comprising a foldable flap (84) extending
generally outwardly away from the conveyor (4),
wherein the packaging apparatus comprises a closing station (14) located downstream
of the loading station (12) for closing the pocket with a second web (16) of packaging
material,
characterized in that
the second web (16) of packaging material is oriented in the closing station (14)
so as to engage with the first web (16) of packaging material and also fold the foldable
flap (84) downwardly with respect to the conveyor (4) as the conveyor (4) moves from
upstream to downstream.
6. The packaging apparatus according to claim 5, characterized in that the second web of packaging material follows an arcuate path toward the conveyor
so as to engage an upstream side of the foldable flap and fold the foldable flap downwardly
with respect to the conveyor.
7. The packaging apparatus according to claim 5 or 6, characterized in that the apparatus comprises at least one movable dog located upstream of the engagement
between the first and second webs of packaging material, the movable dog folding the
foldable flap downwardly with respect to the conveyor, wherein, preferably,
the at least one movable dog rotates to engage with the foldable flap as the conveyor
carries the food product past the at least one movable dog, and/or
the apparatus comprises a servo motor rotating the at least one movable dog, and/or
the at least one movable dog comprises at least one finger for engaging an upstream
side of the foldable flap.
8. The packaging apparatus according to claim 7, characterized in that
the apparatus comprises at least one guide bar located downstream of the movable dog,
the guide rail guiding the foldable flap in a first folded position towards the engagement
between the first and second webs of packaging material.
9. The packaging apparatus according to claim 7 or 8, characterized in that the apparatus comprises a control circuit programmed to control the relative speeds
of the web transport conveyor and the movable dog,
wherein, preferably,
the control circuit controls the speed of the web transport conveyor in a linear indexing
motion and wherein the control circuit controls the movable dog in a non-linear movement,
and/or
the apparatus comprises a position sensor sensing position of the movable dog and
communicating the sensed position to the control circuit, and/or
the apparatus comprises a first servo motor moving the web transport conveyor and
a second servo motor moving the movable dog,
10. The packaging apparatus according to any one of the claims 5 to 9, characterized in that
the engagement between the first and second webs of packaging material folds the foldable
flap into a second folded position.
11. The packaging apparatus according to any one the claims 7 to 10, characterized in that
it comprises a plurality of movable dogs folding the foldable flap downwardly with
respect to the conveyor.
12. The packaging apparatus according to any one of the claims 7 to 11, characterized in that
the at least one movable dog comprises opposing fingers for engaging with an upstream
side of the foldable flap during each 180 degree rotation of the at least one movable
dog.